Simplified arthroscopic rotator interval capsule closure: an alternative technique

Management of Shoulder Instability in Patients with Underlying Hyperlaxity

PURPOSE OF REVIEW

Shoulder instability in patients with underlying joint hyperlaxity can be challenging to treat. Poorly defined terminology, heterogeneous treatments, and sparse reports on clinical outcomes impair the development of best practices in this patient population. This article provides a review of the current literature regarding optimal management of patients suffering from shoulder instability with concomitant hyperlaxity of the shoulder, from isolated shoulder joint hyperlaxity to congenital hypermobility spectrum disorders (HSD).

RECENT FINDINGS

Current research shows specialized physiotherapy protocols focused on strengthening of periscapular muscles and improvement of sensorimotor control are a promising non-surgical therapeutic avenue in certain patients, which can be augmented by device-based intervention in select cases. If surgical treatment is warranted, arthroscopic techniques such as pancapsular shift or plication continue to demonstrate favorable outcomes and are currently considered the benchmark for success. The long-term success of more recent innovations such as coracoid process transfers, conjoint tendon transfers, subscapularis tendon augmentation, and capsular reconstruction remains unproven. For patients affected by connective tissue disorders, treatment success is generally less predictable, and the entire array of non-operative and operative interventions needs to be considered to achieve the best patient-specific treatment results. In the treatment of shoulder instability and concomitant hyperlaxity, specialized physiotherapy protocols augmented by device-based interventions have emerged as powerful, non-operative treatment options for select patients. Successful surgical approaches have been demonstrated to comprehensively address capsular redundancy, labral lesions, and incompetence of additional passive stabilizers in a patient-specific fashion, respective of the underlying connective tissue constitution.

Biomechanical effects of rotator interval closure in shoulder arthroplasty

BACKGROUND

Subscapularis dysfunction remains a significant problem after shoulder arthroplasty. Published techniques have variable recommendations for placing a rotator interval closing suture in attempts to off-load the subscapularis repair site, the implications of which have yet to be examined in the literature. The goals of this study were to investigate the biomechanical benefit of the rotator interval closing suture on the subscapularis repair strength and to analyze the effect on shoulder range of motion.

METHODS

Sixteen matched cadaveric shoulders underwent a subscapularis tenotomy and shoulder arthroplasty. The subscapularis tenotomy was repaired, and motion at physiologic torsional force was recorded. One of each matched pair was randomly assigned to receive an additional rotator interval closure suture. Each specimen then underwent a standardized cyclic loading with measurement of gap formation and load to failure.

RESULTS

The rotator interval closing suture significantly increased the ultimate load to failure of the subscapularis repair (452 N vs. 219 N; P = .002) and decreased gap formation at the subscapularis repair site. Measurement of the shoulder motion showed no significant difference between shoulders with and without the rotator interval closing suture.

DISCUSSION

We report the additional biomechanical benefit that the rotator interval closing suture provides to the subscapularis repair site after shoulder arthroplasty. This suture acts to improve the load to failure of the subscapularis repair and to decrease gap formation under cyclic load. Furthermore, it does not detrimentally affect shoulder external rotation or overall arc of rotation. Our findings support the application of this off-loading technique after subscapularis repair during shoulder arthroplasty.

The Rotator Interval of the Shoulder: Implications in the Treatment of Shoulder Instability

Biomechanical studies have shown that repair or plication of rotator interval (RI) ligamentous and capsular structures decreases glenohumeral joint laxity in various directions. Clinical outcomes studies have reported successful outcomes after repair or plication of these structures in patients undergoing shoulder stabilization procedures. Recent studies describing arthroscopic techniques to address these structures have intensified the debate over the potential benefit of these procedures as well as highlighted the differences between open and arthroscopic RI procedures. The purposes of this study were to review the structures of the RI and their contribution to shoulder instability, to discuss the biomechanical and clinical effects of repair or plication of rotator interval structures, and to describe the various surgical techniques used for these procedures and outcomes.

Rotator Interval Lesion and Damaged Subscapularis Tendon Repair in a High School Baseball Player

In 2013, a 16-year-old baseball pitcher visited Nobuhara Hospital complaining of shoulder pain and limited range of motion in his throwing shoulder. High signal intensity in the rotator interval (RI) area (ball sign), injured subscapularis tendon, and damage to both the superior and middle glenohumeral ligaments were identified using magnetic resonance imaging (MRI). Repair of the RI lesion and partially damaged subscapularis tendon was performed in this pitcher. During surgery, an opened RI and dropping of the subscapularis tendon were observed. The RI was closed in a 90° externally rotated and abducted position. To reconfirm the exact repaired state of the patient, arthroscopic examination was performed from behind. However, suture points were not visible in the >30° externally rotated position, which indicates that the RI could not be correctly repaired with the arthroscopic procedure. One year after surgery, the patient obtained full function of the shoulder and returned to play at a national convention. Surgical repair of the RI lesion should be performed in exactly the correct position of the upper extremity.

Arthroscopic rotator interval closure in shoulder instability repair: a retrospective study

BACKGROUND

Arthroscopic Bankart repair (ABR) is a standard treatment for recurrent anterior shoulder instability. Young age, hyperlaxity, loss of bone stock and multidirectional or voluntary type of instability are all associated with failure of this procedure. Rotator interval laxity is associated with shoulder instability, whereas rotator interval closure increases humeral head stability and reduces shoulder range of motion.

METHODS

The records of patients with recurrent anterior shoulder dislocations who underwent ABR with or without arthroscopic rotator interval closure (ARIC) in our department between 1999 and 2007 were reviewed. Rates of recurrent dislocation or symptomatic subluxation as well as functional outcome were evaluated using Walch-Dupley score.

RESULTS

Three (8.1%) of the 37 ABR+ARIC patients (age 19-44 years, 32 males) had re-dislocated their shoulder at 42±16 months following the procedure, all of which had systemic joint hyperlaxity. Six (13%) of the 46 ABR patients (age 19-39 years, 42 males) had re-dislocated their shoulder at 13±14 months, three of which had systemic joint hyperlaxity and dislocated their shoulder within 1 year following the operation. Systemic joint hyperlaxity (28% of ABR and 41% of ABR+ARIC patients) was significantly associated with recurrent dislocation and poor functional outcome. ABR+ARIC patients had slightly more limited range of motion with similar good and excellent functional results (75%) at final follow up time.

CONCLUSIONS

Systemic joint hyperlaxity is a risk factor for failure of ABR. When ARIC is performed in combination with ABR, it may have an additive effect on shoulder stability.

Quantification of active ROM after arthroscopic Bankart repair with rotator interval closure

Several series report patients homogeneously treated using arthroscopic Bankart repair exclusively, or in some cases arthroscopic Bankart repair with rotator interval closure. Current international literature has few reports on arthroscopic Bankart repair with rotator interval closure procedures undertaken on a homogeneous series of patients. The purpose of this study was to evaluate the residual active range of motion (ROM) and clinical outcome in this patient population. Fourteen patients affected by recurrent anterior instability were consecutively treated. Rowe, Walch-Duplay, and UCLA scores, as well as differences in active ROM of both shoulders (treated and contralateral), were recorded. A significant reduction in active external rotation was noted along the side of the arm (P<.001) and at 90 degrees of abduction (P=.007). The average reduction was 12.14 degrees and 7.21 degrees, respectively, which represents 17.8% and 8% of the arc of motion of the opposite side in external rotation. No significant differences were found for flexion, abduction, and internal rotation. According to Walch-Duplay and Rowe scores, 71.4% and 85.7% of patients had excellent or good results. Arthroscopic Bankart repair with rotator interval closure results in a reduction of external rotation and provides satisfactory stability results.

The addition of rotator interval closure after arthroscopic repair of either anterior or posterior shoulder instability: effect on glenohumeral translation and range of motion

BACKGROUND

Although the use of rotator interval closure is frequently advocated as a useful supplement to shoulder instability repairs, the addition of a rotator interval closure after arthroscopic instability repair has not been fully investigated.

PURPOSE

The objective of this study was to investigate whether a rotator interval closure improves glenohumeral stability in an anterior and posterior instability shoulder model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fourteen fresh-frozen cadaveric shoulder specimens were dissected free of soft tissues, leaving the rotator cuff intact with simulated cuff loading. All specimens were mounted in a custom testing apparatus using infrared sensors to document glenohumeral translation and rotation. The specimens were then tested for stability in the following order: vented/subluxated state, after arthroscopic anterior (Group 1; 7 specimens) or posterior (Group 2; 7 specimens) instability repair with suture anchors, and then after rotator interval closure. For each of the 3 testing conditions, the following were measured: (1) external and internal rotation at neutral, (2) external and internal rotation at 90 degrees of abduction, (3) posterior and anterior translation at neutral rotation (15 N and 25 N), (4) anterior translation at 90 degrees of abduction and external rotation (Group 1; 15 N and 25 N), (5) posterior translation at 90 degrees of flexion and internal rotation (Group 2; 15 N and 25 N), and (6) sulcus testing in neutral (7.5 N).

RESULTS

Posterior stability was only improved after anchor capsulolabral repair (8.0 to 5.0 mm; P = .017, 25 N), but there was no improvement after rotator interval closure (5.0 to 4.6 mm; P = .453). However, anterior stability was improved after capsulolabral repair (8.6 to 4.0 mm; P = .016, 25 N) and also improved further by rotator interval closure (4.0 to 2.4 mm; P = .007). The mean loss of external rotation was significantly increased by the addition of the rotator interval closure in both neutral and abducted glenohumeral positions, with a mean external rotation loss of 28 degrees in neutral (P = .013). The addition of a rotator interval closure did not improve sulcus stability (P = .4).

CONCLUSION

The addition of an arthroscopic rotator interval closure after posterior capsulolabral repair did not improve posterior stability; however, anterior stability was improved further after a rotator interval closure. Inferior stability was not improved. Arthroscopic rotator interval closure significantly decreased external rotation at both neutral and abducted arm positions.

CLINICAL RELEVANCE

Arthroscopic closure may be beneficial in certain cases of anterior shoulder instability; however, posterior instability was not improved. Predictable losses of external rotation after rotator interval closure are of concern.

Rotator interval dimensions in different shoulder arthroscopy positions: a cadaveric study

The rotator interval was defined as a triangular structure, where the base of the triangle was the coracoid base, the upper border was the anterior margin of the supraspinatus, and the lower border was the superior margin of the subscapularis muscle-tendon unit. We evaluated the rotator interval dimensions in 15 shoulders from 10 lightly embalmed adult cadavers in 3 shoulder arthroscopy positions: 0 degrees of abduction and 30 degrees of flexion (beach chair [BC]), 45 degrees of abduction and 30 degrees of flexion (lateral decubitus 1), and 70 degrees of abduction and 30 degrees of flexion (lateral decubitus 2). In each shoulder position, measurements were made in neutral rotation (NR), 45 degrees of external rotation (ER), and 45 degrees of internal rotation (IR). The coracoid base lengthened with IR in all positions and shortened in ER in the lateral decubitus position but not in the BC position. Abduction significantly lengthened the coracoid base, which was shortest in the BC position with ER (24 +/- 4 mm) and longest in the lateral decubitus 2 position with IR (33 +/- 5 mm). The coracoid base, where sutures are placed during plication of the interval, was observed to lengthen and, therefore, loosen with IR and abduction. To prevent postoperative ER restriction, plication should be made in ER or neutral rotation when operating in the BC position and the degree of abduction should be decreased and the shoulder held in ER when operating in the lateral decubitus position.